<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>学习keyframes</title>
  <style>
    .container{
      width: 200px;
      height: 200px;
      background-color: pink;
      animation: 3s ease-in infinite reverse slidein;
    }
    @keyframes slidein {
      from {
        transform: translateX(0%);
      }

      to {
        transform: translateX(100%);
      }
    }
  </style>
</head>
<body>
  <div class="container"></div>
</body>
</html>